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Sint-Truiden, Belgium

Bangels E.,Pcfruit vzw
Communications in agricultural and applied biological sciences | Year: 2012

Codling moth (Cydia pomonella) is one of the most important pests in apple and pear. In 2010 mating disruption became a key pest management tactic in Flemish pip fruit orchards, largely due to a government subsidy and demonstrating projects aiming to widen the area treated by pheromones as large as possible. As a consequence, the mating disruption strategy was applied at approximately 7.500 ha, or half of the pip fruit area, in 2010 and 2011. The sudden large-scale implementation of this technique changed the codling moth management landscape. Here we present a case study of a commercially managed orchard that suffered from high codling moth pressures for many years, as did the surrounding area. The RAK3 mating disruption system was introduced at this location in 2010, and was continued in 2011. Systematic detailed codling moth flight data for this location are available for many years. In addition, comprehensive data on damage levels of chemically untreated windows spread all over the test orchard in a randomized block design were obtained in successive years, enabling us to thoroughly evaluate the effect of the changed codling moth management strategy. Data from 2011 included damage levels in chemically treated windows when the entire orchard was applied once at the flight peak of Cydia pomonella. In 2009, before introduction of mating disruption, a mean of 8.25 +/- 5.54% of the fruits were infested at harvest when assessed in completely untreated windows. After two years of mating disruption, supported with a full chemical support in 2010, except for the untreated assessment windows, and only one application on the flight peak of 2011, damage was reduced to less than 0.03% at harvest. This is a valuable case study to demonstrate the benefits of the mating disruption approach. Source

Goossens D.,Pcfruit vzw
Communications in agricultural and applied biological sciences | Year: 2011

During summer the parasitoid Aphelinus mali may certainly reduce the infestation of woolly apple aphid (Eriosoma lanigerum), but studies on the single interaction rarely indicate sufficient biological control in the period May-June. In this period chemical control by spirotetramat or pirimicarb remains indispensable in order to anticipate on dense migration waves and subsequent colonization of extension shoots by E. lanigerum. The limited parasitation by A. mali around flowering is linked with a delayed emergence from diapause and with a slower reproduction rate than its host. In 2010 and 2011 the first adult flights monitored on yellow sticky traps corresponded perfectly with the currently used prediction models for A. mali. Further accurate monitoring all along the season enabled also to determine a well defined endo-parasitic phase of A. mali occurring after the small peak observed around flowering. During this endo-parasitic phase A. mali larvae reside inside their mummified host. Compounds with higher acute toxicity on A. mali adults, like chloronicotinyl insecticides (CNI's), are preferably positioned here. Selectivity in the time can then be claimed. Respecting this principle, the further parasitation potential of A. mali in summer is not hampered. Preservation of the first peak of flights of A. mali in the pre-flowering period is essential for an exponential flight increase. This is essential for the parasitation of E. lanigerum in summer, which constitutes a valuable complement in the integrated control strategy. Source

Belien T.,Pcfruit vzw
Communications in agricultural and applied biological sciences | Year: 2012

A key element of integrated pest management (IPM) is the suppression of potential pest outbreaks by beneficial arthropods. The European earwig, Forficula auricularia L., is an important natural enemy of a wide range of insect pests in pip fruit orchards. However, earwig population sizes vary greatly from location to location, illustrating their sensitivity to biotic and abiotic factors, especially human interventions relating to orchard management. In order to help growers sparing and augmenting earwig populations in their pip fruit orchards, we developed a software tool that integrates a sophisticated earwig phenology model with management recommendations. The program is based on a day degree model for earwigs which is fed by temperature data collected by the pcfruit research centre. In addition, a pesticide database with known side effects of a wide range of products on the different life stages of earwigs is integrated in the system. The output gives the current status of the earwig population and management recommendations for activities critical for their survival. Hence, by consultation of this user-friendly software fruit growers can predict the earwig development in the field at any time, and organize the timing of orchard management actions taking into account the presence of (sensitive) life stages of the earwig life cycle. Doing so, negative effects specific orchard management actions, such as badly timed spray applications and soil tillage, can be avoided. Source

Schoofs H.,Pcfruit vzw | Verjans W.,Pcfruit vzw | Deckers T.,Pcfruit vzw | De Maeyer L.,Bayer CropScience | Bylemans D.,Pcfruit vzw
Acta Horticulturae | Year: 2015

Since the use of the antibiotic Streptomycin is forbidden in Belgium, new strategies to control fire blight have been developed like the use of Plant Defense Enhancing (PDE) molecules. Aliette (fosetyl-Al) has been registered against fire blight in Belgium in 2012 as a PDE molecule with applications starting in the postfloral period on pear and at the end of bloom on apple. A PDE molecule like fosetyl-Al should be positioned preventively, prior to the infection, so that the defense mechanisms of the plants can be switched on in time. A reduction in the disease progression and a clear reduction in the ooze formation on the infected tissues were observed on plants treated 3 times preventively with fosetyl-Al and this is considered to be a very interesting factor in the fire blight epidemiology. Furthermore, after hail during the summer period, fosetyl-Al can interfere with the ooze formation on the infected immature fruits and lower the disease spread. To protect the flowering period, the efficacy of the bacterial antagonist Bacillus subtilis, is tested. The antagonistic bacteria Bacillus subtilis can act against fire blight through a competition with Erwinia amylovora for site and nutrients on the stigma of the flowers and through the production of antimicrobial peptides. In 2013 and 2014, the efficacy of different formulations of Bacillus subtilis QST 7013, applied alone or in combination with fosetyl-Al, was assessed against artificial inoculations of flower clusters and young, active growing shoots on potted 'Conference' pear trees under optimal infection conditions in the quarantine greenhouse. The results showed interesting activity of the bacterial antagonist against Erwinia amylovora: a reduction in the disease progression as necrosis and a limitation of the ooze formation on the infected tissue was observed. A combination of the protection of blossoms with Bacillus subtilis followed by the PDE activity of fosetyl-Al looks promising. Source

Delele M.A.,Catholic University of Leuven | Tsige A.A.,Catholic University of Leuven | Tijskens E.,Catholic University of Leuven | Nicolai B.M.,Catholic University of Leuven | And 3 more authors.
Acta Horticulturae | Year: 2010

Inefficiency in fungicide treatment is one of the reasons for postharvest decay of fruits during the storage period. Postharvest treatment of fungicides using thermonebulisation fogging systems offers a promising means to minimize such postharvest decay. Moreover, this treatment method reduces the use of fungicides in the orchards, minimizes residues on the fruits and improves ecological and environmental sustainability. A three-dimensional computational fluid dynamics (CFD) model was developed to help optimize the application of the fungicide particles inside the fruit storage room. An Eulerian-Lagrangian multiphase flow model was used. The model takes into account two-way coupling with turbulent dispersion of the particles. The particle diameter distribution at the exit of the thermonebuliser was measured and used as an input to the model. The product loaded in vented bins was considered as a porous medium, where the loss coefficients to the three orthogonal directions were approximated using simulation of the flow through the vented boxes and stacks. The dynamic behaviour of the fan was also taken into account. The distribution of the fungicide particles was highly affected by the air flow distribution inside the room. Good agreement was found between measured and predicted results of deposition of fungicide particles. Source

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